The business, which runs 37 hospitals throughout the UK and treats more than 930,000 patients every year, said that revenues had increased 3.7pc to £643m last year and earnings before factors such as tax rose 12pc year-on-year to £168.4m.

Spire's revenue is drawn from patients with insurance, those who pay out of their own pocket and providing services to the NHS.

While private medical insurance-funded hospital activity contracted slightly last year, the number of self-funding patients increased 3.2pc year-on-year. Rob Roger, Spire chief executive, said the latter had helped to compensate for some of the effect of a contraction in insurance-funded activity and that Spire had also seen an expansion in its work with the NHS, which comprises around 25pc of Spire's business.

He added that Spire's investment in outpatient and diagnostic facilities had helped drive top-line growth. Last year, Spire opened Shawfair Park Hospital in Edinburgh, with services such as an outpatient and diagnostics centre, and a fertility clinic.

Mr Roger said that Spire's results demonstrated "continual growth and operational improvement of the business, despite the challenge of the economic downturn".

"This, in addition to a continued focus on engaging with our staff, delighting our patients and working in partnership with consultants, has led to significant improvements – ultimately improving the quality of care we offer," he added.

Garry Watts, who was chief executive of SSL International before it was bought by Reckitt Benckiser and is now executive chairman of Spire, said: "The private sector has a very important role to play in healthcare in the UK.

"Our three years of acquisition and investment in new and upgraded facilities has firmly established Spire as one of the UK's leading private healthcare providers and has extended our reach into new and innovative services."

Healthcare providers have been in the spotlight of late amid the debate over the Government's planned reforms to the NHS. Mr Roger said he believed the private sector was "part of the solution going forward".

"If people lack confidence in terms of when they are going to be seen, if there's a chance that waiting times will increase, what tends to happen is people come to the private sector as an alternative," he added.

Earlier this year, a survey of more than 500 GPs carried out by Spire found that 77pc said they were experiencing cuts in fertility services in their area, 70pc were seeing reductions in weight-loss treatment and 40pc were experiencing restrictions in ophthalmology services.

At the time, Dr Jean-Jacques de Gorter, Spire clinical director, said that he would expect an increase in referrals for weight loss surgery and fertility treatment to private hospitals as the NHS faces increasing budget constraints.